1. Field of the Invention
The present invention relates to a head suspension for a disk drive incorporated in an information processing unit such as a personal computer.
2. Description of Related Art
A head suspension (hereinafter referred to also as “suspension”) for a disk drive has a base plate and a load beam welded to an end of the base plate. The base plate is used to attach the suspension to a carriage arm of the disk drive. In the disk drive, the suspension is arranged in a space between the carriage arm and a disk. The suspension has a certain height that hinders the miniaturization of the disk drive.
To reduce the height of the suspension, Japanese Patent No. 3089360 discloses a suspension 101 shown in FIGS. 1 and 2. The suspension 101 has a long base plate 103 and a load beam 105 welded to the long base plate 103. The long base plate 103 has a pivot hole 107, which is correctly fitted to a carriage in a disk drive. The prior art uses the long base plate 103 as a carriage arm, to reduce a space between adjacent disks 109 and miniaturize the disk drive.
This prior art, however, has some problems. The flatness of the long base plate 103 is deteriorated when the pivot hole 107 is directly formed through the long base plate 103. The long base plate 103 must secure rigidity because it must serve as a carriage arm. To secure the rigidity, the long base plate 103 has a specified thickness. If the pivot hole 107 is formed through the long base plate 103 by etching, the accuracy of the pivot hole 107 will be low due to the thickness of the long base plate 103. Accordingly, the long base plate 103 with the pivot hole 107 must be formed by press.
The holing by press leaves residual deformation on the long base plate 103, to deteriorate the flatness of the long base plate 103.